effects of osmosis on plant tissue

• Osmosis


  Diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• Effect of osmosis on plant tissue

  1. Peel potato

  2. Use cork board to produce cylinders

  3. Trim cylinders to same length

  4. Measure length and mass of cylinders

  5. Place cylinders in test tubes with different solutions

  6. Leave overnight

  7. Remove cylinders, gently roll on paper towel

  8. Measure length and mass of cylinders again
• Plant cell in water


  Water moves into the cell by osmosis, cell expands
• Plant cell in concentrated solution


  Water moves out of the cell by osmosis, cell shrinks
• Percentage change


  Calculated as: (change in value / original value) x 100
• Calculating percentage change


  • Potato cylinder starting mass 1.56g, increases by 0.25g - 16.03% increase
  • Potato cylinder starting mass 1.32g, decreases by 0.19g - 14.39% decrease
• Distilled water used instead of tap water to avoid dissolved substances affecting osmosis
• Graph of percentage change in mass/length vs sugar solution concentration shows:

  • In water, cylinder gains mass as water moves in by osmosis
  • In concentrated sugar solution, cylinder loses mass as water moves out by osmosis
  • Where line crosses x-axis, no change in mass as concentration inside and outside cell is equal